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Lars Peter Lindfors - One of the best experts on this subject based on the ideXlab platform.
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Hydrogenation of 2,2-Dimethylol-1-butanal and 2,2-Dimethylol-1-propanal to Trimethylolpropane and Trimethylolethane over a Supported Nickel Catalyst
Industrial & Engineering Chemistry Research, 2002Co-Authors: Tiina-kaisa Rantakylä, Tapio Salmi, Päivi Mäki-arvela, Tapio Ollonqvist, Jyrki Kuusisto, Juhani Väyrynen, Lars Peter LindforsAbstract:The hydrogenation kinetics of 2,2-dimethylol-1-butanal (TMP-aldol) and 2,2-dimethylol-1-propanal (TME-aldol) over a supported Nickel catalyst were determined with experiments carried out in a batchwise operating autoclave at 50−90 °C and 40−80 bar hydrogen. Water was used as the solvent. TMP- and TME-aldol were hydrogenated with 100% selectivity to the corresponding triols. The effects of the catalyst activation procedure and the formaldehyde concentration on the hydrogenation kinetics were studied with thermogravimetry, X-ray photoelectron spectroscopy, and hydrogenation experiments. Catalyst reduction at a high temperature (400 °C) under hydrogen flow was favorable because of a more effective reduction of Nickel Oxides. Formaldehyde had a considerable retarding effect on the aldol hydrogenation: the hydrogenation rate was low until all of the formaldehyde was hydrogenated to methanol. The hydrogenation rate of TME-aldol was found to be significantly lower than that of TMP-aldol at low temperatures and ...
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Hydrogenation Kinetics of 2,2-Dimethylol-1-butanal to Trimethylolpropane over a Supported Nickel Catalyst
Industrial & Engineering Chemistry Research, 2000Co-Authors: Tiina-kaisa Rantakylä, Tapio Salmi, Jeannette Aumo, Päivi Mäki-arvela, Rainer Sjöholm, Tapio Ollonqvist, And Juhani Väyrynen, Lars Peter LindforsAbstract:The hydrogenation kinetics of 2,2-dimethylol-1-butanal (TMP-aldol) over a supported Nickel catalyst was determined with experiments carried out in a batchwise operating autoclave at 50−90 °C and 40−80 bar hydrogen. The reaction mixture was analyzed with gas and liquid chromatography. It was found that TMP-aldol can be hydrogenated with a 100% selectivity to the corresponding triol, trimethylolpropane. The effects of the catalyst activation procedure and the formaldehyde concentration on the hydrogenation kinetics were studied. The hydrogenation experiments revealed that catalyst reduction at a high temperature (400 °C) under hydrogen flow was favorable for the catalyst performance. The reason was a more effective reduction of Nickel Oxides which was confirmed with thermogravimetry and X-ray photoelectron spectroscopy. The presence of formaldehyde had a considerable retarding effect on the aldol hydrogenation kinetics: the hydrogenation rate was low until all of the formaldehyde was hydrogenated to methan...
Tiina-kaisa Rantakylä - One of the best experts on this subject based on the ideXlab platform.
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Hydrogenation of 2,2-Dimethylol-1-butanal and 2,2-Dimethylol-1-propanal to Trimethylolpropane and Trimethylolethane over a Supported Nickel Catalyst
Industrial & Engineering Chemistry Research, 2002Co-Authors: Tiina-kaisa Rantakylä, Tapio Salmi, Päivi Mäki-arvela, Tapio Ollonqvist, Jyrki Kuusisto, Juhani Väyrynen, Lars Peter LindforsAbstract:The hydrogenation kinetics of 2,2-dimethylol-1-butanal (TMP-aldol) and 2,2-dimethylol-1-propanal (TME-aldol) over a supported Nickel catalyst were determined with experiments carried out in a batchwise operating autoclave at 50−90 °C and 40−80 bar hydrogen. Water was used as the solvent. TMP- and TME-aldol were hydrogenated with 100% selectivity to the corresponding triols. The effects of the catalyst activation procedure and the formaldehyde concentration on the hydrogenation kinetics were studied with thermogravimetry, X-ray photoelectron spectroscopy, and hydrogenation experiments. Catalyst reduction at a high temperature (400 °C) under hydrogen flow was favorable because of a more effective reduction of Nickel Oxides. Formaldehyde had a considerable retarding effect on the aldol hydrogenation: the hydrogenation rate was low until all of the formaldehyde was hydrogenated to methanol. The hydrogenation rate of TME-aldol was found to be significantly lower than that of TMP-aldol at low temperatures and ...
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Hydrogenation Kinetics of 2,2-Dimethylol-1-butanal to Trimethylolpropane over a Supported Nickel Catalyst
Industrial & Engineering Chemistry Research, 2000Co-Authors: Tiina-kaisa Rantakylä, Tapio Salmi, Jeannette Aumo, Päivi Mäki-arvela, Rainer Sjöholm, Tapio Ollonqvist, And Juhani Väyrynen, Lars Peter LindforsAbstract:The hydrogenation kinetics of 2,2-dimethylol-1-butanal (TMP-aldol) over a supported Nickel catalyst was determined with experiments carried out in a batchwise operating autoclave at 50−90 °C and 40−80 bar hydrogen. The reaction mixture was analyzed with gas and liquid chromatography. It was found that TMP-aldol can be hydrogenated with a 100% selectivity to the corresponding triol, trimethylolpropane. The effects of the catalyst activation procedure and the formaldehyde concentration on the hydrogenation kinetics were studied. The hydrogenation experiments revealed that catalyst reduction at a high temperature (400 °C) under hydrogen flow was favorable for the catalyst performance. The reason was a more effective reduction of Nickel Oxides which was confirmed with thermogravimetry and X-ray photoelectron spectroscopy. The presence of formaldehyde had a considerable retarding effect on the aldol hydrogenation kinetics: the hydrogenation rate was low until all of the formaldehyde was hydrogenated to methan...
P Oustadakis - One of the best experts on this subject based on the ideXlab platform.
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utilization of jarosite alunite residue for mortars restoration production
Materials and Structures, 2010Co-Authors: M Katsioti, S Agatzinileonardou, P E Tsakiridis, O Mauridou, A Moropoulou, E Aggelakopoulou, P OustadakisAbstract:The present study was carried out to produce artificial hydraulic lime mortars for repair and conservation of historic masonry using a jarosite/alunite precipitate, a waste product of a novel Greek hydrometallurgical process developed to treat economically low grade Nickel Oxides ores. Alternative mortars were prepared by mixing lime powder, quartz sand and the above residue, substituting lime up to 50%. The mortars were prepared and tested according to European Norm EN 1015. They were cured for periods of 28 and 90 days and the compressive and flexural strengths were determined. The best mechanical behavior was observed for the mortar with 50% lime replacement, which also presented a low ratio of compressive to flexural strength (f c/f f). X-Ray diffraction, TG-DTA and mercury porosimetry were used to characterize the hydration products at 28 and 90 days. The results showed that the jarosite/alunite residue was dissolved in the high alkaline environment of the mortar, producing CaSO4 · 2H2O and AlOOH. During hydration, gypsum and some of the Ca(OH)2 were consumed, together with aluminum hydroxide in order to produce ettringite, a fact that improved the mechanical behavior of the produced mortars.
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examination of the jarosite alunite precipitate addition in the raw meal for the production of sulfoaluminate cement clinker
Journal of Hazardous Materials, 2006Co-Authors: M Katsioti, P E Tsakiridis, S Leonardouagatzini, P OustadakisAbstract:The aim of the present research work was to investigate the possibility of adding a jarosite-alunite chemical precipitate, a waste product of a new hydrometallurgical process developed to treat economically low-grade Nickel Oxides ores, in the raw meal for the production of sulfoaluminate cement clinker. For that reason, two samples of raw meals were prepared, one contained 20% gypsum, as a reference sample ((SAC)Ref) and another with 11.31% jarosite-alunite precipitate ((SAC)J/A). Both raw meals were sintered at 1300 degrees C. The results of chemical and mineralogical analyses as well as the microscopic examination showed that the use of the jarosite-alunite precipitate did not affect the mineralogical characteristics of the so produced sulfoaluminate cement clinker and there was confirmed the formation of the sulfoaluminate phase (C4A3S), the most typical phase of this cement type. Furthermore, both clinkers were tested by determining the grindability, setting time, compressive strength and expansibility. The hydration products were examined by XRD analysis at 2, 7, 28 and 90 days. The results of the physico-mechanical tests showed that the addition of jarosite-alunite precipitate did not negatively affect the quality of the produced cement.
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examination of the jarosite alunite precipitate addition in the raw meal for the production of portland cement clinker
Cement and Concrete Research, 2005Co-Authors: P E Tsakiridis, S Agatzinileonardou, P Oustadakis, M Katsioti, E MauridouAbstract:Abstract The aim of the present research work was to investigate the possibility of adding a jarosite–alunite chemical precipitate, a waste product of a new hydrometallurgical process developed to treat economically low grade Nickel Oxides ores, in the raw meal for the production of Portland cement clinker. For that reason, two samples of raw meals were prepared, one with ordinary raw materials, as a reference sample ((PC)Ref) and another with 1% jarosite–alunite precipitate ((PC)J/A). Both raw meals were sintered at 1450 °C. The results of chemical and mineralogical analyses as well as the microscopic examination showed that the use of the jarosite–alunite precipitate did not affect the mineralogical characteristics of the so produced Portland cement clinker. Furthermore, both clinkers were tested by determining the grindability, setting time, compressive strength and expansibility. The hydration products were examined by XRD analysis at 2, 7, 28 and 90 days. The results of the physico-mechanical tests showed that the addition of jarosite–alunite precipitate did not negatively affect the quality of the produced cement.
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examination of the jarosite alunite precipitate addition in the raw meal for the production of portland and sulfoaluminate based cement clinkers
International Journal of Mineral Processing, 2005Co-Authors: M Katsioti, S Agatzinileonardou, P E Tsakiridis, P OustadakisAbstract:Abstract The aim of the present research work was to investigate the possibility of adding a jarosite–alunite chemical precipitate, a waste product of a new hydrometallurgical process developed to treat economically low grade Nickel Oxides ores, in the raw meal for the production of Portland cement clinker. The precipitate was also tested in the production of non-expansive, sulfoaluminate-based cement clinker, as a substitute for gypsum because of its high sulfate content. For the Portland clinker, two samples of raw meals prepared, one with ordinary raw materials (reference sample) and another with 1% jarosite–alunite precipitate. Both raw meals were sintered at 1450 °C. For the sulfoaluminate-based clinker, one raw meal contained 20% gypsum (reference sample) whereas the other contained 11% of the precipitate. Both raw meals were sintered at 1300 °C. The results of chemical and mineralogical analyses as well as the microscopic examination showed that the use of the jarosite–alunite precipitate did not affect the mineralogical characteristics of the so produced Portland cement clinker. In the case of sulfoaluminate-based cement clinker, there was confirmed the formation of the sulfoaluminate phase (C4A3S¯), the most typical phase of this cement type.
Päivi Mäki-arvela - One of the best experts on this subject based on the ideXlab platform.
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Hydrogenation of 2,2-Dimethylol-1-butanal and 2,2-Dimethylol-1-propanal to Trimethylolpropane and Trimethylolethane over a Supported Nickel Catalyst
Industrial & Engineering Chemistry Research, 2002Co-Authors: Tiina-kaisa Rantakylä, Tapio Salmi, Päivi Mäki-arvela, Tapio Ollonqvist, Jyrki Kuusisto, Juhani Väyrynen, Lars Peter LindforsAbstract:The hydrogenation kinetics of 2,2-dimethylol-1-butanal (TMP-aldol) and 2,2-dimethylol-1-propanal (TME-aldol) over a supported Nickel catalyst were determined with experiments carried out in a batchwise operating autoclave at 50−90 °C and 40−80 bar hydrogen. Water was used as the solvent. TMP- and TME-aldol were hydrogenated with 100% selectivity to the corresponding triols. The effects of the catalyst activation procedure and the formaldehyde concentration on the hydrogenation kinetics were studied with thermogravimetry, X-ray photoelectron spectroscopy, and hydrogenation experiments. Catalyst reduction at a high temperature (400 °C) under hydrogen flow was favorable because of a more effective reduction of Nickel Oxides. Formaldehyde had a considerable retarding effect on the aldol hydrogenation: the hydrogenation rate was low until all of the formaldehyde was hydrogenated to methanol. The hydrogenation rate of TME-aldol was found to be significantly lower than that of TMP-aldol at low temperatures and ...
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Hydrogenation Kinetics of 2,2-Dimethylol-1-butanal to Trimethylolpropane over a Supported Nickel Catalyst
Industrial & Engineering Chemistry Research, 2000Co-Authors: Tiina-kaisa Rantakylä, Tapio Salmi, Jeannette Aumo, Päivi Mäki-arvela, Rainer Sjöholm, Tapio Ollonqvist, And Juhani Väyrynen, Lars Peter LindforsAbstract:The hydrogenation kinetics of 2,2-dimethylol-1-butanal (TMP-aldol) over a supported Nickel catalyst was determined with experiments carried out in a batchwise operating autoclave at 50−90 °C and 40−80 bar hydrogen. The reaction mixture was analyzed with gas and liquid chromatography. It was found that TMP-aldol can be hydrogenated with a 100% selectivity to the corresponding triol, trimethylolpropane. The effects of the catalyst activation procedure and the formaldehyde concentration on the hydrogenation kinetics were studied. The hydrogenation experiments revealed that catalyst reduction at a high temperature (400 °C) under hydrogen flow was favorable for the catalyst performance. The reason was a more effective reduction of Nickel Oxides which was confirmed with thermogravimetry and X-ray photoelectron spectroscopy. The presence of formaldehyde had a considerable retarding effect on the aldol hydrogenation kinetics: the hydrogenation rate was low until all of the formaldehyde was hydrogenated to methan...
Tapio Salmi - One of the best experts on this subject based on the ideXlab platform.
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Hydrogenation of 2,2-Dimethylol-1-butanal and 2,2-Dimethylol-1-propanal to Trimethylolpropane and Trimethylolethane over a Supported Nickel Catalyst
Industrial & Engineering Chemistry Research, 2002Co-Authors: Tiina-kaisa Rantakylä, Tapio Salmi, Päivi Mäki-arvela, Tapio Ollonqvist, Jyrki Kuusisto, Juhani Väyrynen, Lars Peter LindforsAbstract:The hydrogenation kinetics of 2,2-dimethylol-1-butanal (TMP-aldol) and 2,2-dimethylol-1-propanal (TME-aldol) over a supported Nickel catalyst were determined with experiments carried out in a batchwise operating autoclave at 50−90 °C and 40−80 bar hydrogen. Water was used as the solvent. TMP- and TME-aldol were hydrogenated with 100% selectivity to the corresponding triols. The effects of the catalyst activation procedure and the formaldehyde concentration on the hydrogenation kinetics were studied with thermogravimetry, X-ray photoelectron spectroscopy, and hydrogenation experiments. Catalyst reduction at a high temperature (400 °C) under hydrogen flow was favorable because of a more effective reduction of Nickel Oxides. Formaldehyde had a considerable retarding effect on the aldol hydrogenation: the hydrogenation rate was low until all of the formaldehyde was hydrogenated to methanol. The hydrogenation rate of TME-aldol was found to be significantly lower than that of TMP-aldol at low temperatures and ...
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Hydrogenation Kinetics of 2,2-Dimethylol-1-butanal to Trimethylolpropane over a Supported Nickel Catalyst
Industrial & Engineering Chemistry Research, 2000Co-Authors: Tiina-kaisa Rantakylä, Tapio Salmi, Jeannette Aumo, Päivi Mäki-arvela, Rainer Sjöholm, Tapio Ollonqvist, And Juhani Väyrynen, Lars Peter LindforsAbstract:The hydrogenation kinetics of 2,2-dimethylol-1-butanal (TMP-aldol) over a supported Nickel catalyst was determined with experiments carried out in a batchwise operating autoclave at 50−90 °C and 40−80 bar hydrogen. The reaction mixture was analyzed with gas and liquid chromatography. It was found that TMP-aldol can be hydrogenated with a 100% selectivity to the corresponding triol, trimethylolpropane. The effects of the catalyst activation procedure and the formaldehyde concentration on the hydrogenation kinetics were studied. The hydrogenation experiments revealed that catalyst reduction at a high temperature (400 °C) under hydrogen flow was favorable for the catalyst performance. The reason was a more effective reduction of Nickel Oxides which was confirmed with thermogravimetry and X-ray photoelectron spectroscopy. The presence of formaldehyde had a considerable retarding effect on the aldol hydrogenation kinetics: the hydrogenation rate was low until all of the formaldehyde was hydrogenated to methan...